Stuffer crimper

ABSTRACT

Improvements in a stuffer, crimper unit having a pair of feed rolls wherein the central positions of side plates urged against both side faces of said feed rolls are located apart from the nip of the feed rolls eccentrically with respect to the line connecting centers of both feed rolls and line perpendicular thereto and said side plates are held in position in holders so that they are freely rotatable to prevent uneven abrasion of the side plates and increase the efficiency of the apparatus.

United States Patent Sokichl Aoki;

Yoshinobu Murakami, both of Mauuyamashi, Japan [2]] Appl. No. 880,130

[ 22] Filed Nov. 26, 1969 [45] Patented Aug. 24, 1971 [73] Assignee Tefiin Limited Kits-kn, Osaka, Japan I 72] Inventors [5 41 STUFFERCRIMPER lClaim,9DnwingFigs.

s21 U.S.CL 28/145 511 lnt.Cl 00291/12 so FieldolSearch ..28/1.6,1.7, 72.14

[56] References Cited UNITED STATES PATENTS 3,093,867 6/1963 Chandler 28/l.6 3,160,941 12/1964 Wil1iamson.. 28/1.6 3,237,270 3/1966 Dennis 28/1 .6

Primary Examiner-Louis K. Rimrodt Attorney-Sherman and Shalloway ABSTRACT: Improvements in a stuffer, crimper unit having a pair of feed rolls wherein the central positions of side plates urged against both side faces of said feed rolls are located apart from the nip of the feed rolls eccentrically with respect to the line connecting centers of both feed rolls and line per pendicular thereto and said side plates are held in position in holders so that they are freely rotatable to prevent uneven abrasion of the side plates and increase the efiiciency of the apparatus.

Patented Aug. 24, 1971 3,600,716-

3 Shoots-Shut 1 Patented Aug. 24, 1971 3,600,716

3 Shoots-Shoot 2 F/ -J F/ .4

Patented Aug. 24, 1971 3,600,776

3 Sheets-Sheet I STUFFER CRIMPER The present invention relates to improvements in sideplates pressing the side faces of the rolls in a stuffer crimper, and. in particular to sideplates of simple and rotatable structure located in a specified position to eliminate the rapid abrasion of the sideplates and prolong their life.

In a stuffer crimper, a pair of feed rolls are usually used, and the sideplates are disposed on both side faces of these rolls so that fed filaments are not forced out of the side faces. Yarn is fed with the rolls into a stuffing box during which time little friction is caused between the roll surface and filaments and consequently despite the prolonged use of the rolls there is no discernible abrasion on the rolls. However the sideplates .disposed on the end faces are directly rubbed with filaments and feed rolls because the plates are securely positioned; and, thus, during prolonged use the plates are subjected to abrasive injuries. At the contact surface of the plates with the nip of a pair of rolls the fed filaments are urged against the plates by great force, and accordingly cause such abrasion injuries. If the sideplates thus injured are continuously used, the surfaces of the plates will be roughed resulting in fuzzing of the filaments, or clogging of the filaments between the nip roll and the plates will render the apparatus inoperative. Hence replacing of an injured plate with a new one becomes necessary with the attendant results of great expense and the stoppage of operations.

As mentioned above, it is a disadvantage in a stufier crimper for sideplates to be subjected to uneven wear or injuries; and, to eliminate this drawback, various designs have been tried. For instance, a sideplate molded in gear from has been used with a shaft projecting at the outer center of the plate supported in a bearing; and by a pinion or chain that meshes with the peripheral teeth of the plate, the sideplate is continuously or intermittently rotated. In this case the shaftline of the sideplate is often adapted to correspond to the nip of the rolls. Thus the plate rotates to change its contact surface with the feed rolls as time goes on and-to prevent local abrasive injuries. There is no tendency for the plate to be worn away unevenly by the feed rolls as is the case with a conventional secured plate. As the plate, however is mechanically rotated through gears and sprockets as mentioned above with a driving shaft, the mechanism becomes complicated and, moreover, has the disadvantage of easily becoming inoperative due to filaments getting entangled with the mechanical parts. Another drawback of this mechanism is that the rotary shaftline of the sideplate is made concentric with the nip of the rolls. When the plate comes in contact with filaments forced in at the nip, the position there becomes a center of the rotation. Thus the generation of injuries due to the friction with filaments cannot be avoided and the efiect is not different from that of an unrotatable plate.

Another design to overcome uneven wear to sideplates is to rotatably dispose the plates the center of rotation eccentric from the nip of the rolls in a direction normal to the yarn feed direction. In this apparatus, the contact point of the nip with the rotatable plate describes a circle on the plate and causes a linear abrasive injury along the circle. Moreover this injury is deepened in a short time. Hence the effect of prolonging the life of the plate is substantially reduced.

According to the present invention which has improved conventional defects, sideplates are rotatably mounted on the holders to press the side faces of the feed rolls so that the centers of rotation of the plates are eccentric from the nip. The position of eccentricity can be located in any intermediate portion not including two lines one of which connects the centers of both rolls and the other of which passes through the nip at a right angle to the former line in a plane consisting of the side faces of the feed rolls.

The sideplate thus disposed is rotated by friction with the side faces of the rolls by pressing the plate to the side faces ofthe rolls.

It is an object of this invention to increase the efficiency of a stuffer crimper by simplifying sideplate mechanisms for the feed rolls in order not to cause uneven abrasion of the plates.

With reference to the drawings an embodiment of the invention will be described below.

FIG. 1 is a side elevation view of the stuffer crimper;

FIG. 2 is a plan view of the stuffer crimper;

FIG. 3 is a plan view of a sideplate;

FIG. 4 is a sectional view in line A-A of FIG. 3;

FIGS. 5, 6, and 7 are diagrams illustrating the abrasion states when the arrangement of the sideplate is altered; and

FIGS. 8 and 9 are diagrams showing the performance of the sideplate.

Referring to FIGS. 1 and 2, filaments are fed into a stuffer box 4 with a pair of feed rolls 3 and 3' via a thread guide 2 and pressed with a flap 6 having a weight 5 attached therefor to give the filaments a desired crimp. On the end faces of rolls 3 and 3 are placed sideplates 7 and 7' to prevent the filaments from jutting out; and as seen in FIGS. 3 and 4, the sideplates are freely rotatably fitted in indentations of holders 9 and 9' by a thrust bearing 8. Sideplates 7 and 7 along, not holders 9 and 9' make contact with the rolls, by slightly protruding from the holders. Holders 9 and 9' are pressed with presser bars 11 and 11 fitted to a clamp frame 10. Rolls 3 and 3' are rotated in the directions of the arrows by driving shafts 12 and 12'.

As seen in FIGS. 1 and 2, nip b of the feed rolls is aligned with the centers of holders 9' and 9; however, the centers a of the sideplates fitted in the holder are shifted so that the centers are located at an appropriate distance from the nip. Accordingly, the contact areas of plates 7 and 7' with roll 3 differ from the contact areas with roll 3'. It will be appreciated that, when one contact area is greater than the other, the plates are caused to freely rotate in the same direction as that of the roll having the greater contact area. For instance, when the contact surface of roll'3 is greater than that of roll 3, plate 7 is rotated in the same direction as the rotating direction of roll 3' (the arrow direction in FIG. 1).

A study of the causes of sideplate abrasion indicate fundamentally such abrasion is caused by the following conditions. The filaments fed into the feed rolls are pressed in band form with by the feed rolls, and both ends of the filaments in band form are bulged outside at the nip to press against the sideplates such that the band of filaments advances pressing the surfaces of the sideplates, and rubbing them when the plates are fixed. The abrasion of the plates is caused by this rubbing, however after the filaments have passed through the nip, the pressing force decreases rapidly resulting in decreased abrasion. It is easily understood that the trace of abrasion on the plates takes an ellipsoidal form; and the accumulation of these traces makes an abrasion streak when the plates are fixed. When the plates are movable as in the present invention, that is rotatable along the filament running direction, the rotation will alleviate the abrasion of the plate. As the rotating speed of the sideplates draws near the filament feeding speed, friction between the rolls and the filaments lessens to decrease the abrasion. In this case the abrasion appears in the ellipsoidal form also, but owing to the rotation of the plates the abrasion trace moves one after another, resulting in 'an annular abrasion mark. It is desired to have as great an annular area of abrasion as possible, but it has been found that the area varies widely with positions of rotating center a of the plate eccentric from nip b.

The relations between rolls 3 and 3' and plate 7 are shown in FIGS. 5, 6, and 7. The distance between a and b is assumed to be constant despite the displacement of a. In FIG. 5, X denotes a line connecting the centers of the feed rolls and Y is a line perpendicular to X passing through nip b. Let rotating center a of the plate be on Y. Since the plate contacts rolls 3 and 3 with the same contact area, it cannot rotate by frictional contact with the rolls. Thus the rotating speed of the plate is zero. If the plate were to be rotated by external force, an annular abrasion l would be caused. The abrasion trace looks like an ellipse the transverse axis of which corresponds to the width of the annular abrasion 1 However. as plate 7 does not move in FIG. 5, it IS outside the scope of this invention even if rotating center a is eccentric from the nip.

Referring to FIG. 6, when rotating center a is placed on X at roll 3', the plate is subject to the turning effect of roll 3 and rotates at maximum speed. This is desirable, but annular abrasion 1, becomes small in width, and is intensified which is also unfavorable. As clearly seen from the above, in FIG. 5, if the sideplate is forcibly rotated by external force the annular abrasion will supposedly become maximum in area, but as it does not move, abrasion injury will appear on a specific portion of the plate in a short time, whereas in FIG. 6 though the rotating speed of the plate reaches a maximum, the area of the annular abrasion is reduced to a minimum. Thus, of the above positions of plate 7 is unsatisfactory; however, if the rotating center is placed in any intermediate portion as in FIG. 7 by avoiding X and Y, an appropriate rotation and a proper area of annular abrasion can be obtained.

FIG. 8 represents an eccentric position of the plate vs width I of an annular abrasion. When rotating center a of the plate changes its position to right and left with Y as the center with the distance between a and b being constant, annular width 1 varies as shown in the diagram. That is, as the rotating center moves further away from Y, annular width 1 gradually decreases. FIG. 9 represents an eccentric position vs the rotating speed *n of the plate. Around Y, rotating speed n is low, and as the eccentric position moves closer to X, rotating speed It increases. As clearly understood from FIGS. 8 and 9, increases in abrasion area and rotating speed are desirable but both are incompatible. If one increases, the other decreases. Therefore, it is concluded that an eccentric point may be selected in an intermediate portion avoiding X and Y. According to such observation, the eccentric position of rotating center a of the plate is located in a plane composed of the side faces of a pair of feed rolls in'the intermediate portion defined by X, a horizontal line connecting the centers of the rolls, and Y, a vertical line passing through the nip, perpendicular to X but not on X or Y.

The above description is based on the condition that the distance between a and b is constant, but the eccentric position of a may be located in any place on the intermediate portion partitioned by X and Y. Generally speaking, to make rotating center a of the plate eccentric so that'it moves away from the filament-feeding direction in a perpendicular direction causes one contact area of the plate with one roll to differ from the other contact area of the same plate with the other roll. Accordingly, the plate is rotated by the difference in torque rendered by the feed rolls in the same direction as the rotating direction of a roll having a greater contact area. Assuming the distance between a and b to be d along the X direction, the rotating speed of the plate will be approximately directly proportional to d. Further as the plate comes in contact with the fed filaments around the nip of the rolls, its turning effect is made up.

lfrotating center a of the plate is positioned farther from X, the abrasion area becomes greater as seen in FIG. 7 as compared with FIG. 6. That is, the greater the contact area, the

less the depth of abrasion in inverse proportion, and thus the plate can be used for a longer time. Assuming the distance between a and b to be f along Y direction, the greater the distance f, the greater is the abrasion area.

. d and f mentioned above may be determined as follows. That is, as d becomes greater, the torque of the plate becomes great, but it is impossible to make d infinitely great. d is controlled by radius r, of the plate, eccentricity f in the filament feed direction, and allowable interval A of plate mounting. If A225 and the plate is urged against the sides a pair of feed rolls so as to cover the nip and the position of the plate is freely located, r, can be determined from the following equation.

If r, is expressed by the equation \/f l-d=r,, the periphery of the plate corresponds to the nip, and filaments bulge onto of the end faces of the rolls. Thus r, is required to be greater than F+d to some extent or by a. In the ordinary case, it is advisable that a is set to 2 to 30 mm.

If A 2 r and the installation position of the plate is limited within a range of allowable interval A by the drive shafts, etc. of the rolls which protrude to the sides of the rolls, the following equations d-l-r, 5A, and

should be satisfied. Thus d is determined.

On the other hand, the life of the plate is prolonged with increase inf, but it cannot be made great infinitely. As mentioned above, the life is controlled by d and r,, so that +a=r is satisfied. d and f may optionally be selected within a range satisfying said conditions.

An example of a crimping process utilizing a stuffer unit according to the present invention will be described below.

Polyethylene terephthalate 300,000 denier two (filament denier of 3 denier) was run and crimped at a speed of I00 m/min into a crimp stufi'er unit as shown in FIG. 1. Brass sideplates 35 mm. in radius were urged against a pair of feed rolls on both sides so that eccentricity f in the filament feed direction was 10 mm. and eccentricity d perpendicular to the filament feed direction was 12 mm. AZr was satisfied. The life of the plates was 42 hours.

For comparison, the same polyethylene terephthalate tow was crimped under the same conditions as above.

Sample ofplate d mm fmrn Life hr.

No. 1 0 0 2 No. 2 0 I0 2 No. 3 I2 0 II In Nos. 1 and 2, d=0 that is, the rotating center of the plate is located on Y. The torques given to the plate by friction are the same in both the rolls, and the directions of the torques are directly opposite, resulting in no rotation of the plate. As only a specified position on the plate is rubbed by filaments, the durable time of the plate is extremely short.

In No. 3 the plate is eccentric in d direction, and so the plate is rotatable by friction, whereas as f is zero, the locus of contact with filaments described on the plate makes a circular, thick line as shown in FIG. 6. With the contact area being narrow, abrasion by friction deeps in a short time. As compared with Nos. 1 and 2, No. 3 has an increased life. It is still by far inferior to the plate having a life time of 42 hr. in the abovementioned example.

In short, in the conventional crimp stuffer unit consisting of feed rolls the damage of the sideplates for the rolls has been great. For eliminating this drawback, mechanical rotation of the plates has been suggested; however there are some obstacles caused by the complications of mechanism. Simplicity of mechanism and reduced injury of the plates have been found to be necessary conditions.

In the present invention, for simplicity of structure, a rotatable 'sideplate is fitted into the indentation of a holder. The rotation center of the plate is shifted from the nip. In rotating the plates, external force is not used but rather the torque due to the friction between the end faces of the feed rolls and the sideplates is utilized. Finally by enlarging the friction area on the sideplates, the eccentric position of the plates is controlled to prolong the durable time of the plate. That is, let one line connecting the centers of both feed rolls 3 and 3' be X and the other line'perpendicular to X and passing on the nip be Y. The eccentric position is located in the intermediate portion enclosed with two lines X and Y with X and Y excepted.

With such design, no special parts for rotating the sideplates are needed, thereby permitting few malfunctions due to the simple mechanism caused on the plates spreads in a considerably wide range, which prevents the occurrence of a deep, linear abrasion injury. Thus, the whole of contact surface is evenly wom away, and as a result the durable time of the plates is, with a leap, extended 20 times that of conventional ones. With this prolongation of the life, the number of replacements decreases, labor and expenses are cut down, and the efficiency of the unit increases.

We claim:

l. A stuffer crimper comprising a pair of feed rolls, first and second sideplates engaging the side faces of said pair of feed rolls, and first and second holders having recesses in the inner surfaces thereof to freely, rotatably hold said first and second sideplates and urge said first and second sideplates against said feed rolls; the rotational centers of said first and second sideplates being positioned eccentric from the nip of said feed rolls in a plane perpendicular to the side faces of said feed rolls and within areas defined by a first line passing through the centers of said feed rolls and a second line extending perpendicular to said first line and passing through the nip of said feed rolls, said areas not including either of said first or second lines. 

1. A stuffer crimper comprising a pair of feed rolls, first and second sideplates engaging the side faces of said pair of feed rolls, and first and second holders having recesses in the inner surfaces thereof to freely, rotatably hold said first and second sideplates and urge said first and second sideplates against said feed rolls; the rotational centers of said first and second sideplates being positioned eccentric from the nip of said feed rolls in a plane perpendicular to the side faces of said feed rolls and within areas defined by a first line passing through the centers of said feed rolls and a second line extending perpendicular to said first line and passing through the nip of said feed rolls, said areas not including either of said first or second lines. 